Welt turning mechanism for knitting machines



W. BOCK Jan. 19, 1932.

WELT TURNING MECHANISM FOR KNITTING MACHINES Filed Aug. 9, 1929 2 Sheets-Sheet l Jan. 19, 1932. w. BOCK WELT TURNING MECHANISM FOR KNITTING MACHINES Filed Aug. 9, 1929 2 sheets-sheet 2 15 A 52 N WITNESSES L INVENTOR:

\ W'ziizeim Bock.

9 5 m 3% 9 BY W W a. w K

Patented Jan. 19, 1932 UNITED STATES PATENT OFFICE WILHELM BOOK, OF GWYNEDD, PENNSYLVANIA, ASSIGNOR T TURBO KNITTING MACHINE COMPANY, OI LANSDALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA WELT TURNING MECHANISM FOR KNITTING MACHINES Application filed August 9, 1929. Serial- No. 884,600.

This invention relates to mechanism useful more particularly with fiat knitting machines such as are employed in the manufacture of full-fashioned hosiery, to form fold-overs or welts at the tops of the stocking blanks.

A full fashioned knitting machine of the kind referred to ordinarily comprises a multiplicity of separate sections for knlttmg as many individual stocking blanks at one tlme.

In accordance with customary practlce the machine is stopped after the knitting of an initial course of loops on the needles of each of the several heads or sections, and such loops engaged by the hooks of a welting bar 16 through manual manipulation of the latter.

The machine is thereupon started and a length of the fabric produced for each wel t, at the completion of which, the machine is stopped a second time and the loops held on 2 the welting bars transferred to the needles of the corresponding sections, here agaln by manual manipulation of said bars, to close the welts. Now in view of the many knitting heads comprised in such a machine, considerable time is lost in starting and stopping, as well as in the performance of these two manual steps necessary incident to the formation of the welts. The operation is moreover attended very often by loop dropping, notwithstanding employment of skilled help commanding high salaries.

The main object of my invention is to overcome the drawbacks of previous pfractice above pointed out through provision of a simple, reliable and inexpensive mechanism whereby all the steps necessary to the formation of welts are performed automatically and without entailing stoppage of the machines, all to the advantage of increasing the output from the machines and greatly minimizing labor costs.

Still other objects and attendant advantages of this invention will be manifest from the detailed description which follows when taken in connection with the accompanying With reference first more particularly to Fig. I of these illustrations, 1O designates the needle bar of one of a number of knitting sections constituting the machine, which bar is adapted to be reciprocated up and down through suitable connections with a rotary cam, not shown, on the main shaft 11 of the machine, after common practice in this art. Also as usual, the sinkers 12 and the knockovers 13 are independently reciprocated horizontally to cooperate with the needles N on the bar 10, incident to fabric loop formation, likewise by motion derived from the main cam shaft 11, through suitable means, not shown, for the purpose. The knock-overs 13 differ however from the customary type employed in flat knitting machines, in that they are formed with upper and lower ledges 13a, 136, which are separated by horizontal intervals 13c and designed to function as throats to restrain the fabric, as the needles N rise to take new thread. The knock-overs 13' are moreover characterized by having their upper ledges 13a notched, as at 13d, for service as hook members in a manner later on explained.

To automatically close a welt, I provide mechanism which includes a welting bar 15 with projecting hook-like instrumentalities 16 along one edge thereof, said instrumentalities corresponding substantially in number to the needles N in the bar 10. As shown in Fig. I, the Welting bar 15 is supported for horizontal sliding toward and away from the needles N in a grooved guide 17 which is fulcrumed for slight rocking movement on a fixed rod 18 and subject to the downward pull of a helical tension spring 19. The lowermost or rest position of the guide 17 is determinable by a set screw 20 which is ad justable in a longitudinal channel rail 21 of the machine frame. As shown, the Welting bar 15 has a downward projection 22 engaged in the clevised end of the vertical arm 23a of a bell crank lever 23 which is arranged to swing about a fixed center 24 in opposition to a spring 25. The horizontal arm 23?) of the bell crank lever 23 carries a roller 26 for actuation by a rotary cam 27 on the main shaft 11. From Fig. II it will be noted that the cam 27 is splined to the shaft 11 in order that it may be shifted laterally into and out of the plane of the roller 26. Any suitable control means may be provided to shift the cam 27 as aforesaid through the medium of a yoke shifting lever 28 with studs 29 engaging a circumferential groove 30 in the hub of said cam.

Under certain conditions fully explained later herein, the rate of rearward movement of the welting bar 15, i. e., away from the needles N, is governed by a spiral rotary cam 31 designed for cooperation with the arm 23b of the bell crank lever 23. This cam 31- is mounted, with capacity for lateral shifting, on a separate shaft 32 that extends parallel to the main shaft 11; while a yoke lever 33 is here again employed as a means for shifting the cam 31 on the shaft 32 under suitable governance, as suggested above in connection with the cam 27. Normally, the shaft 32 is quiescent with the cam 31 in the position shown in Fig. I; but when required, said shaft is intermittentl rotated through picking of a ratchet wheel 34 by a pawl 35, which is controlled by a guard 36 whereby it is ordinarily held raised from said wheel. The (pawl 35 is however continuously reciprocate by virtue of connection to a rocker arm 37 which is fulcrumed at 38 and carries a roller 39 to run in contact with the cam 40 affixed to the main shaft 11.

To raise and lower the guide 17 for the welting bar 15 on its fulcrum 18, also for a purpose later on explained, I provide means comprising a lever 41 which is rockable on a fixed center 42. At its upper end the lever 41 is fitted with a roller 43 to engage the guide 17 from beneath: and at the lower end said lever carries a roller 44 adapted to be influenced by a rotary cam 45 positioned alongside the cam 27 on the shaft 11, and, like the latter cam, splined to said shaft for lateral shifting thereon. As shown in Fig. II, the cam 45 has two rises 46, 47 separated by a blank cylindrie interval 48 against which the roller 44 on the lever 41 normally reposes. The means for shifting the cam 45 either to the right or the left of the plane of the roller 44 is, as in the two other instances, in the form of a shifting lever 49 that may be governed, if desirable or convenient, b the same means which controls shifting o the cam 27. I

The operation of my invention is as follows: At the beginnin of a stocking, the yarn is laid in the usua way across the needles N and depressed between said needles by the sinkers 12, as shown in Fig. III, to form the loops 'L for the first course. At about this time, the cam 27 is shifted into theprovince of the roller 26 on the bell crank lever 23, and the cam 45 concurrently'moved to the left (as considered with respect to Fig.

II) so that its rise 47 is brought into the plane of the roller 44 on the lever 41. As the welting bar 15 is moved inward toward the needles N, through the action of cam 27 on the bell crank lever 23, it is raised slightly through lifting of the guide 17 by the lever 41 under the influence of the first step 470:, of the rise 47, of the cam 45. This redetermines registry as between the hoo instrumentalities 16 of the welting bar 15 and the hooks 13d of the knock-overs 13, as shown in Fig. III, when said bar has reached the inner limit of its horizontal movement. In descending, the needles N draw the loops L into the aligned notches of the instrumentalities 16 and the knock-overs 13, as in Fig. IV. Upon consummation of the foregoing, the second or higher step 476, ofthe rise 47, on the cam 45, through action upon the lever 41, causes the guide 17 for the welting bar 15 v to be raised still more to the end that the 100 s L are lifted from the hooks 13d of the knoc overs 13, as shown in Fi V, by the instrumentalities 16 of the we ting bar 15 just as the latter begins its retractive movement 1ncident to passing of the high portion of the cam 27 by the roller 26 on the bell crank lever 23. At this period in the cycle, the spiral cam 31 is shifted into position over the arm 23?) of the bell crank lever 23, and the pawl 35 released to pick the ratchet wheel 34. The control of the welting bar 15 is thus given over for a time to the cam 31, which, through being intermittently rotated by the pawl 35, initiates and controls gradual recession of said welting bar 15 under pull of the bell crank lever 23 by the spring 25, the welt fabric F being thus taken up progressively as successive courses are knit on the machine. By the time the cam 31 has made substantially a complete revolution, a sufficient length of the fabric F is produced to permit folding thereof over a rod 50, Fig. I, for attachment to the strap 51 of the usual take-up roller 52 in the well known way. The cam 31 after having performed the function described, is drawn to an inactive position from above the arm 23?) of the crank lever 23, and the pawl 35 raised to cease picking the ratchet wheel 34. When finally a predetermined length of fabric F has been knit for the welt, as shown in Fig. I, the cam 27 is once more shifted into active position, and the cam 45 concurrently moved, this time to the right, to bring the rise 46 in line with the roller 44 on the lever 41. Accordingly, as the rise 46 of the cam 45 encounters the roller 44, the guide 17 for the welting bar 15 is raised so that, as said bar is advanced by action of the cam 27, the hook instrumentalities 16 are once more brought into registry with the hooks 13d of the knockovers 13, and incidentally place the loopsL over said hooks 13d, as shown in Fig. VI. Just as the welting bar 15 is about to recede upon movement of the high portion of the cam 27 past the roller 26 on the bell crank lever 23, the roller 44 on the lever 41 drops off the rise 46 of cam 45 with attendant lowering of the hook instrumentalities 16, as shown in Fig. V II, to enable their withdrawal from the loops L and permit retainment of said loops by the knock-over hooks 1303 as the welt bar 15 continues to recede. When thus on the hooks 13d of the knock-overs 13, the loops L are in line with the needles N which finally pass up through said loops and, by friction with said loops, lift them from the hooks 13d, as shown in Fig. VIII, with re-' sultant completion of the welt formation.

Having thus described my invention, I claim:

1. The combination in a flat knitting machine comprising a series of needles; of welt mechanism including a slidable bar with a series of hooks, and automatic mechanism whereby the bar is manipulated horizontally and upward to engage its books with the initial course of knitting on the needles, then moved away from the needles gradually as the weltfabric is being knit, and subsequently similarly moved toward the needles after a completion of a definite length of such fabric for transfer of the loops on its hooks to said needles to close the welt.

2. The combination in a flat knitting machine comprising a series of needles; of welt mechanism including a slidable'bar with a series of books, and automatic mechanism whereby the bar is first manipulated horizontally and slightly upward to engage its hooks with the initial course of knitting on the needles, then moved away from the needles gradually as the welt fabric is being knit, then after completion of a definite length of such Welt fabric, similarly moved toward the needles for transfer of the loops on its hooks to said needles and closing the welt, and subsequently manipulated to dislodge its hooks from the loops.

3. The combination in a fiat knitting machine comprising a series of needles; of welt automatic means whereb the bar is moved horizontall forward-in t e uide toward the needles an rocked upward y to engage the hooks with the loops of the initial course of knitting on said needles, then gradually retracted in the guide as the welt fabric is being knit, and subsequently similarly moved forward in the guide a second time after knitting of a definite length of the welt fabric for transfer of the loops on its hooks to the needles to close he welt.

4. The combination in a flat knitting machine comprising a series of needles; of welt mechanism including a welting bar with a series of books, a guide supporting the bar for sliding movement relative to the needles, and automatic means whereby the bar is moved horizontally'forward in the guide to engage the loops of the initial course of knitting on the needles, then back in the. guide during knitting of the welt fabric and similarly moved forward a second time in the guide to close the welt, and the guide intermittently rocked independently to facilitate loop engagement and disengagement incident to the operations aforesaid.

' 5. The combination in a flat knitting machine comprising a series of needles; of welt mechanism including a welting bar with a is closed, and the guide intermittently rocked slightly on its fulcrum to facilitate loop engagement and disengagementincident to the operations aforesaid.

6. The combination in a flat knitting machine having hooked loop engaging members individually associated with its needles; of welt mechanism including a slidably welting bar with a series of hooks, and automatic 'chine'comprising a series of needles and co operating knock-overs with loop engaging hooks; of welt mechanism including a slidable welting bar with a corresponding series of books, and automatic means for manipulating the bar horizontally and slightly upwards to engage its hooks with the loops of the initial course of knitting on the needles,

then moving the bar gradually away from the needles as the welt fabric is being knit, then after completion of a definite length of such fabriqmoving the bar similarl toward the needles, and finally rockin sai bar upwardly and downwardly to p ace the loops held by its hooks on the hooks of the knockovcrs for impalement by the needles and closure of the welt.

In testimony whereof, I have hereunto signed my name at Lansdale, Pennsylvania, this 6th day of August, 1929.

WILHELM BOCK. 

